The present invention relates generally to dental implants, and particularly to a dental implant delivery system and method for using the system.
Dental implants are typically packaged and shipped in a package that includes an implant delivery system. The implant delivery system is maintained in a sterile environment and is opened just before the implant is needed during the surgical implantation procedure.
FIG. 1A illustrates an example of one such prior dental delivery system shown generally at 10. Delivery system 10 includes a vial 12 housing a threaded implant 14 and a driver mount 16.
The vial (shown as a partial cross-sectional view) has an elongated cylindrical configuration forming an internal cavity with a shoulder 13. The vial is used to transport the implant and driver mount. A lid (not shown) fits on top of the vial to seal and retain the implant and driver mount.
Implant 14 is shown having an external threaded section 18 and a top coronal section 20. The coronal section includes a hexagonal projection 22 for mating with different dental components, such as a dental abutment.
The driver mount includes a bottom portion having a hexagonal recess 24 that engages with the hexagonal projection 22 on the implant. The driver mount also includes a bottom portion, a top portion, and a flange 26 extending outwardly between these two portions. This flange has a disc shape and has a larger diameter than the bottom portion.
A screw 28 secures the driver mount to the implant. Once connected, the driver mount and implant together fit within the internal cylindrical cavity formed within the vial. The flange 26 rests on the internal shoulder 13 to hold the implant and the driver mount in the vial and keep the implant from touching the sides or bottom of the vial.
In order to install implant 14 into a patient""s jawbone, an implant site is prepared using conventional surgical procedures. Typically, an incision is made along the gingival tissue at the implant site, and a cylindrical bore is drilled into the jawbone. Once the drilling steps are finished and the site is fully prepared, the implant is ready to be inserted into the jawbone. First, a wrench, such as a motorized dental hand-piece, is fitted with a driving tool and then to the end of the driver mount. Typically the driving tool functions as an adapter between the wrench and the driver mount attached to the top of the implant. The driving tool is then used to remove the implant and driver mount from the vial. The end of the implant is fit within the bore of the jawbone, and the drive tool drives the implant into position within the bone. Once the implant is driven to the desired depth, the driving tool is removed from the end of the driver mount. Then, the screw 28 holding the driver mount is removed from the implant. If the implant has been placed in soft bone, the torque used to remove the driver mount screw may also act to unscrew the entire driver mount-implant assembly. In these cases, a countertorque tool is fitted to the driver mount to prevent the driver mount from rotating as the driver mount screw is removed. Now, the driver mount can be detached from the end of the implant. Once the driver mount is removed, the coronal end of the implant is exposed and must be covered. A separate healing cap (not shown) is obtained and positioned at the coronal end of the implant. A tool, different from that used to drive the implant, is used to screw the healing cap to the implant. The gingival tissue is then sutured, and the implant remains within the bone for several months as osseointegration and healing occur. During a second surgical procedure, the implant is re-exposed, the healing cap is removed, and a dental prosthesis is affixed to the implant.
FIGS. 1B and 1C show a prior art dental implant delivery system taught in U.S. Pat. No. 5,622,500 entitled xe2x80x9cInsertion Tool/Healing Collar/Abutment.xe2x80x9d A healing collar 50 has an opening 52 that engages a male projection 54 of dental implant 56. A screw 58 passes through the healing collar and threads into an internal cavity 60 to connect the healing collar to the implant. A separate cover screw 62 screws into the top of the screw 58. The implant, healing collar, and screws are packaged in a cylindrical container 64 that surrounds a vial 66. A stopper 68 fits on top of the vial and holds the implant and healing collar at one end and the cover screw at an opposite end.
In order to place the implant, the stopper 68 is removed from the vial 66 and transported to the implant site. The distal end of the implant is positioned into the bore in the jawbone until the stopper frictionally disengages from the healing collar. Then, a driving tool (not shown) is inserted into an opening 72 of the healing collar in order to drive the implant into the jawbone. The driving tool is removed, and the cover screw 62 is positioned onto the top of screw 58. Another dental driving tool is then inserted into a passage 74 of the cover screw to screw it into the screw 58.
Prior dental implant delivery systems have numerous disadvantages. One important disadvantage is that numerous surgical steps are required to implant a dental implant. As discussed above, these steps include uninstalling a driver mount, installing a healing cap, and changing driving tools several times. If many of these steps could be eliminated, the surgical implantation procedure would be much simpler, quicker, easier to learn, safer, and ultimately more efficient.
Another disadvantage is that prior delivery systems require various different tools and components to implant the dental implant. For example, a separate driver mount and driver mount screw are connected to the implant. Then, a driving tool connects to the driver mount to drive the implant into the bone. A countertorque tool and driver mount screw removal tool are then used to remove the driver mount and its screw. Next, a separate healing cap and accompanying healing screw are placed on the end of the implant. Yet another driving tool is then used to tighten the healing cap. If many of these tools and components were eliminated, fewer parts would be required to install an implant; and a significant cost savings could be realized.
Another disadvantage is that during the implantation procedure, the internal cavity of the implant may be susceptible to bacteria or other foreign material. Once the implant is driven into the jawbone, the driver mount is removed, and the internal cavity of the implant is exposed until the healing cap is positioned over this cavity. During the time before the healing cap is in place, bacteria or other foreign material may get inside the internal cavity of the implant. These trapped contaminants may increase the probability of infection, or solidify during the healing screw process, forming an adhesive glue inside the implant. This glue can make the healing cap difficult to remove during subsequent procedures. Elimination or reduction of this occurrence would provide benefits to the patient and doctor.
Another disadvantage is that the driver mount may add unwanted length or width to the delivery system. For example, some driver mounts (like the one shown in FIG. 1) are wider than the implant. In some instances then, it may be difficult or impossible to completely position the wide driver mount within tight inter-dental spaces. In particular, during a single tooth restoration, the implant often must be driven between two adjacent teeth, and the distance between these teeth may be too narrow to accommodate the driver mount. As another example, prior driver mounts add additional length to the end of the driving tool/driver mount/implant assembly. This additional length may make it difficult or impossible to properly position and then drive the implant into the bone. In particular, some locations in the posterior mandible or maxilla cannot be accessed if the implant, driver mount, and driving tool form an overall length that is too long.
As another disadvantage, the driver mount can occlude the view of the anti-rotational feature on the end of the implant. Most dental implants have an anti-rotational feature (such as a hexagon, octagon, or plurality of tines) at the coronal end that engages with a corresponding dental component, like an abutment. During some implantation procedures (for example, installation in the anterior mandible or maxilla), the doctor may need to view the orientation of these anti-rotational features once the implant is seated to the proper depth in the jawbone. In order to obtain this view, the driver mount must first be removed. If the implant is not correctly oriented, then the driver mount must be re-installed and the implant rotated to the correct position.
The present invention solves the problems discussed with prior dental delivery systems and provides further advantages.
The present invention is directed toward a dental implant delivery system that includes a dental implant, a driving tool, and a healing screw. The healing screw both drives the implant into the jawbone during implantation and protects the coronal end of the implant during osseointegration. The dental implant may be installed in the jawbone of the patient with a greatly reduced number of surgical steps and tools.
The dental implant includes a distal end, a threaded section, and a coronal end. The coronal end includes an engaging feature (such as a hexagon or Spline tines) and a threaded bore extending into the body of the implant.
The driving tool includes two ends. One end connects to a dental wrench (such as a motorized dental handpiece), and the other end connects to and engages with the healing screw.
The healing screw includes a separate shaft and collar. The shaft has external threads at one end to threadably engage the threaded bore of the implant. The other end of the shaft connects to the collar and has a bore extending into the body of the shaft. The collar fits around the shaft and includes two engaging regions: one region engages the driving tool, and the other region engages the engaging feature at the coronal end of the implant. In the preferred embodiment, the shaft is able to rotate while connected to the collar. As such, the collar can be engaged with the engaging feature of the implant while the shaft is threaded into the threaded bore of the implant, thus seating the healing screw on the implant.
The delivery system of the present invention is particularly advantageous because the number of steps required to implant a dental implant is very small. The delivery system does not include a separate driver mount since the healing screw functions to drive the implant. As such, no steps are required to install or remove a separate driver mount or like component. Further, the healing screw also functions to protect and cover the coronal end of the dental implant. The healing screw is connected to the coronal end of the implant by the manufacturer. As such, a separate healing cap does not have to be installed on the coronal end of the dental implant during the implantation procedure. Further yet, one single tool is required to install the implant into the jawbone. Separate tools for driving the implant, removing the driver mount screw, holding the driver mount with removing the driver mount screw, and installing the healing cap are not required. Further yet, the risk of contaminating the implant or dropping one of the dental components is greatly reduced since the number of surgical steps and number of components are minimized.
The following summary briefly describes the method using the implant delivery system of the present invention and illustrates the small number of surgical steps required to implant a dental implant: During the implantation procedure, the implantation site is prepared using conventional techniques. Once the site is prepared, the dental implant and connected healing screw are obtained. The driving tool engages the tool engaging region of the healing screw, and the dental implant is moved to the implantation site. Once at the implantation site, the driving tool drives the implant and healing screw into the jawbone. The healing screw functions as a driver mount while the implant is driven into the bone. In this regard, the healing screw transfers torque from the driving tool to the implant. After the implant is fully seated in the jawbone, the driving tool is disengaged from the healing screw. The healing screw is left on the coronal end of the implant. Now the healing screw functions as a conventional healing cap and protects the coronal end of the implant. At this point, the implantation procedure is complete, and the implantation site can be closed using conventional techniques.
As another advantage, once the implant is driven to the desired location, no components (such as a driver mount or conventional healing cap) need to be removed from or added to the implant. The healing-screw of the present invention is connected to the dental implant by the manufacturing during packaging. As such, movement and disturbance of the implant are minimized. With the delivery system of the present invention, once the implant is driven to the correct position and orientation, the healing screw serves as the noted healing cap. Typically, this healing screw will not be removed until sometime later when the dental prosthesis is ready to be attached to the implant.
As another advantage, various different tools are not required to implant the dental implant of the present invention. In the present delivery system, a single driving tool is needed to implant the implant. The driving tool engages the tool engaging region of the healing screw to carry or transport the implant to the implantation site. Then, the same driving tool (while still connected to the healing screw) drives the implant into the jawbone. Once the implant is positioned into the jawbone, the driving tool is removed. No other tools are required to install the implant.
As another advantage, the internal cavity of the implant is continuously covered and thus less susceptible to bacteria or other foreign material. The healing screw of the present invention is placed on the coronal end of the implant during packaging. During the implantation procedure, the implant is removed from the packaging, and the implant is positioned into the jawbone. The healing screw is not removed during these surgical steps and, thus, continuously helps to seal and protect the coronal end of the implant.
As another advantage, the delivery system of the present invention does not include a separate driver mount that adds unwanted length or width to the delivery system. The healing screw fits snugly on the implant and adds a very small amount of additional height to the coronal end. Further, the healing screw is sized to have about the same diameter as the implant, so no additional width is added. The implant delivery system of the present invention thus can be used in instances when access to the restoration site is narrow or limited in space or when the interdental space is very small or narrow.
As another advantage, the view of the anti-rotational feature on the end of the implant is not occluded. While the healing screw is positioned on the end of the implant, the anti-rotational features are visible. As such, no components (such as a driver mount or healing cap) need to be removed during the implantation procedure to view the orientation of the anti-rotational features.
As yet another advantage, the implant procedure minimizes the amount of handling or contact with the components of the implant delivery system and other tools. As such, the likelihood that a component may be dropped, mishandled, contaminated, or otherwise misplaced is greatly reduced.
As another advantage, fewer steps are required to place the implant. This reduces the time required for surgery. This time increases the profitability of the surgical procedure for the surgeon, and also reduces discomfort to the patient. The reduced number of steps also makes the surgical procedure easier to learn and remember. This is beneficial to the inexperienced surgeon or someone who places dental implants infrequently.
As another advantage, the number of disposable parts supplied with each implant is reduced. The healing screw of the present invention replaces a driver mount, driver mount screw, and healing cap. This results in substantial cost savings.
As another advantage, a reduced and more consistent healing screw removal torque is achieved. Preferred embodiments of the healing screw require a small frictional engagement between the collar and shaft. This frictional engagement greatly reduces the probability of spontaneous screw loosening of the healing screw during the healing period, which can endure for several months. The two-piece design of the healing screw also prevents loads on the collar from being directly transferred as loosening torque to the threaded shaft. The reduced probability of healing screw loosening allows a reduced initial tightening torque to be used. This initial lower torque is can also be more consistent as it is applied by the manufacturer during packaging under controlled conditions and using precision torque tightening equipment.
As yet another advantage, the position of the implant can be easily adjusted at any time during placement. Prior art healing caps are typically made of the same material as the implant itself. Once a prior art healing cap has been attached to the implant, neither the orientation of the implant""s anti-rotational features nor the vertical position of the implant""s abutment mounting surface can be easily discerned. In contrast, the preferred embodiments of the invention utilize a different, visually contrasting material for the collar of the healing screw than for the implant. This allows easily visual identification of the critical implant-to-abutment interface. The surgeon can identify both the angular orientation and the vertical height of the implant at all times, and can adjust both at any time without removing a typical healing cap or remounting any kind of typical driver mount.